Shaqs out. Again. Lots of nagging injuries have been bothering him. So far this season, hes had sore knees, bad hips, a painful Achilles tendon and now a foot injury.

Celtics fans dont even seem bothered by it. Sure, theres worry about the big guy in the playoffs, but most fans seem sympathetic to a middle-aged guy (he turned 39 Sunday) with nagging injuries still playing in the NBA.

Not me.

And heres why the issue is Shaqs size. The Big Diesel has become a Double-wide. Shaq needs to lose weight. There, I said it.

When a basketball player jumps, his knees and ankles are designed to act as shock absorbers to take the impact. This is a combination of the joints bending and cartilage flexing. There are even little sacs of fluid called bursas that absorb the force.

So thats what we need to focus on if we want to protect Shaqs knees, hips and ankles the force of the landing. Shaq is listed by the Celtics at 325 pounds. Please. I went back and looked at Shaq in his Magic and Laker days. My educated guess is that hes tipping the scales between 350 and 360 pounds, up maybe 50 pounds from when he entered the league. Thats under 3 pounds of gain a year they just add up.

His weight becomes magnified when you look at force of impact, though. Thats because you multiply the players weight by the effect of gravity pulling him to the floor to measure force of impact. The effect of gravity has been found to be 32.2. Thats right, each pound counts 32 times when measuring the force.

So say Shaq weighs 350 pounds. Every time he jumps, his legs absorb an amazing 11,270 pounds of force. This season, Shaq is averaging 5.5 FGA per game. Those are all dunks and lay-ups, so thats 61,985 pounds of force. Hes averaging 4.9 boards per game, so theres another 55,223 pounds of force. His 2.3 blocks per game add another 25,921 pounds of force. And we should assume another 5 jumps or so on block attempts and missed boards for another 56,350 pounds of force. Thats over 200,000 pounds of force every game.

Lets compare to another big guy to get a sense of how big this is. KG is listed at 220 pounds, which I can believe. The impact of each of his jumps is only 7,084. So KGs average game of 11.8 FGA (assume 8 dunks and lay-ups), 9.2 boards, 0.8 blocks and the same 5 assumed missed blocks and boards only comes up to 162,932 pounds of force. Look at that double the production of Shaq and way less force to deal with.

The big difference is the weight.

Heres another thing: Shaq has bad hips and a bad back. The pelvic bone is like a see-saw balanced on the hips - the more weight is piled in front, the more strain felt by the hips and lower back. I learned in med school that every extra pound a man carries on his gut means 10 pounds of pressure on the low back.

For the sake of argument, say Shaq split the difference between his Magic weight and his Celtic weight. Hed get down to 325, you know, the weight the Cs say he is.

That would be a reduction in impact force of 10 percent, which is huge. Would that lead to 10 percent more production? I say yes. Would that lead to 10 percent more games played? Once again, I say yes.

I never even got to the important reasons Shaq should lose weight heart disease, diabetes and stroke risk are the big ones. I just write about it from an injury point of view.

Cmon, Shaq. Lose the weight. Do it for your career. Do it for Celtics fans. Most importantly, do it for your kids.